The present invention relates to a production method for producing flat tubes from at least one strip of endless band material having at least one wall part and having an inner part which is formed with corrugations on a roller train provided with roller pairs, with the strip running in the longitudinal direction through the rollers and being shaped, and with the inner part formed with corrugations being placed between the shaped wall part, after which closure of the flat tube is carried out. The present invention also relates to a roller train on which the method is carried out, and to a heat exchanger having the produced flat tubes.
The method steps stated above can be gathered from earlier-filed German patent application no. DE 10 2006 029 378.9. With reference to this document, required for producing flat tubes is a roller train which, for example depending on the desired geometry of the inner part or of the “endless” strip from which the inner part is generated, could extend over more than 10-20 m, requires considerable investment capital. The substantive matter is indicated in FIG. 16 of German patent application no. DE 10 2006 029 378.9, which is present as FIG. 22 of this application. As FIG. 15 of German patent application no. DE 10 2006 029 378.9 shows, during the course of the production of the corrugations 70 of the inner part, the width of the strip is correspondingly reduced and the number of corrugations 70 is increased, which influences inter alia the installation expenditure of the roller train because numerous roller pairs 60 are required.
FIG. 5 in DE 198 00 096 A1 likewise shows a plurality of roller pairs. Also described in DE 198 00 096 A1 is the production of corrugated plates.